#!/usr/bin/perl
# 
# Exercise 11.10
# 
# (Extra credit) Given an atom and a distance, find all other atoms in a PDB file that 
# are within that distance of the atom.
#
# Answer to Exercise 11.10
#
# Since this is an extra credit problem I won't give the answer here.  It's fairly easy to 
# do, anyway.  You just have to know how to calculate the distance between two points in
# 3-dimensional space; and how to extract the x, y, and z coordinates from an ATOM record type.
# The first you can easily find; the second you can figure out, perhaps with a look at the
# PDB reference material.
